<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
  <style>
    .s1{
        width: 100px;
        height: 100px;
        background-color:black ;
        border-radius: 5px;
        display: flex;
        justify-content: center;
        align-items: center;


    }
    .ss1{
        width: 40px;
        height: 40px;
        border-radius: 50px;
        background-color: aliceblue;
    }
  </style>
</head>
<body>
    <div class="s1">
      <div class="ss1"></div>
    </div>
</body>
</html>